Cutting oil



Patented 1, 1936 PATENT OFFICE? CUTTING on.

Louis A. Herrmann, Jersey City, N. J., and Theodore G. Roehner, Malverne, N. Y., assignoi's to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York v No Drawing.

Application December 14, 1934,

Serial No. 757,467 9 Claims. (0!.87-9) This invention is directed to improvements in cutting oils, and particularly to improvemen in the so-called soluble cutting oils.

Cutting oils are used in the lubrication of machine tool work, being applied at the point of contact of tool and work in such operations as lathe work, drilling, gear cutting, broaching and the like.

The functions of a cutting oil are to lubricate the point of contact of the tool and work, and

of the tool and chip; also to carry away heat, to avoid the overheatingof the tool or work. Failure-ofeither function willgive rise to consequent bad effects on' the work, short useful life of tool between sharpening 1 or reshaping and the like. The characteristics by which cutting oils are judged are -such things as speed with which work may be performed with a given lubricant without serious overheating, etc;

degree of cooling for a given speed of working, freedom from corrosion of'finished surfacesof work, stability of lubricant ingredients, freedom from ingredients of an infectious nature or likely to carry infection,stability underrepeated re-use, and the like.

For certain classes of lubrication in this art, there have been used what are known-as soluble oils, or soluble cutting oils. These oils are hydrocarbon oils of mineral or animal origin, vto which has. been added a proportion of some com-.

pound capable of enabling the oil to be suspended as an oil-water emulsion, the emulsion being applied as the cutting lubricant and coolant. It is specifically with oils of this type that this invention has to do.

Oils of this type heretofore commonly used .consist mainly of a hydrocarbon oil, together with an emulsifier. The oil maybe all of'mineral origin or may have a varying proportion of oils, such as degras or cas'tor exceptionally greater service than similaroils not containing available sulphur.

.An object of this invention is to: providesoluable cutting oils containing substantial and ef* fective proportions of readily available sulphur.

A further object is to provide such oils in which the sulphur is present in a stable form capable of withstanding storage and repeated re-use. Another object is toprovide such oils with the property of emulsifying with water of any degree of hardness usually found. Further 9bjects are the provision of oils of this ;-type'with ,varying percentages of availablefsulphui'..freedom from offensive odor, freedonr from infectious characteristics, and such further objects as I may hereinafter app ar. 8,

As an example of one producteinbodyingthe invention,we' may cite the followingcomposition.

- Formula I, 1

Weight per cent 10 Emulsifying base .--a '20.0 Non-corrosive base 10.0

Parafllne il 70.0

The physical propertiesof the resulting prod-" uct are as follows: f. i

Gravity, A. P. I 19.5 Flash, open "F 350 Fire,'F" '400 Pour, "F 2020 Saybolt viscosity F 450" Color, A. S. T. M Dark 8 f The amounts of ingredients used in thisformula may be'varied between the following limits. j Min. Max. Emulsifying base wei'ght per cent ..;.10 50 Non-corrosive.base weight per. cent... '5, 25 Parafline oil weight per cent -.'85 25 In the above formula, the emulsifying base used is a sulphonated mineral oilplus'i soda soaps of oleic acid; and rosin, cbntainingjsome'free oleic acid. For this emulsifyingbase theregmay be, substituted any of the commonly usedemulsifying bases, such as soaps of oleic'acids,of other animal and/or vegetable acids, or the socalled mahogany. acids, which aresulphonates derived from the treating ofipetrolelum: oils with" sulphuric acid.

The "non-corrosive base formed by reacting together theIIQ1 9W D8 j 'gredients.

Similar sulphur-bearing bejniadefb! sulphurizing many animal. fish, vegetable-and other oils such as sulphurizedvoleic andst'earic- 50 acids, sulphurized whale oil,- sulphurized aoyav bean oil, sulphurized hydrocarbon oils, sulphurized terpenes, and thelike. These sulphurized" oils are characterized by the presenceoi sulphur in dissolved form, asdisting'uished on the one as is *aiccmpound 4 j particle form in suspension, and on the other hand'from compounds containing sulphurin a closely bonded chemical combination from which the sulphur may not be separable and available under conditions of cutting oil useto lend anin- .creased lubricating ability to the compound.

These sulphurized bases are formed by heating together proper proportions of oil and sulphur (S. U. V.) at 100 F. upward, the heavier oils being used for services characterized by higher loading. This soluble sulphurized cutting oil is made by agitating the various ingredients together in a steam jacketed kettle at IOU-150 F.

until uniformly blended and then drawing into drums. An emulsion thereof made by stirring one volume of the finished oil into fifteen volumes of tap water should show only slight separation after standing 48 hours.

Similarly effective soluble lubricant oils may be made after the following formula.

Formula II Weight per cent Emulsifying base 20.0 Sulphurized mineral oil 80.0

The physical properties of the resulting product are as follows:

Gravity, A. P. I 19.8 Flash, open F 360 Fire, "F v 420 Pour, F 25 Saybolt viscosity 100 F 410" Color, A. S. T. M Dark? In this formula, the base is the same as previously used, or any of the equivalents above noted. The sulphurized mineral oil is formed by dissolving about 1.5% of sulphur, by weightjin a light parafline oil of approximately 150 seconds viscosity, (Saybolt Universal), at 100 F., by heating the oil and sulphur together until combination is effected. The oil used may be any light parafline oil, less viscous or more viscous. The sulphur content of the oil may be varied from 0.5 per cent to 4.0 per cent.

In the above formula, the proportions of the ingredients may be varied from about 10% of emulsifying base as a minimum to about 50% of that base as a maximum.

The above formulae are capable of emulsification to a stable suspension in waters of the ordinarily neutral grade; In waters of extreme 6. hardness emulsions made with soluble oils are frequently unstable and have relatively poorer 1 lubricant value. In order to correct this, there may be added to these novel cutting oils, as for I instance, those manufactured under Formula II,

from about 8 per cent to about 30 per cent of a I compound which we designate as a potash-rosin oil soap base. This ingredient is usually added in amounts of from 10 per cent to 17 per cent, this range being capable of handling waters of the i usual range of hardness. A typical preferred percentage of this ingredient is 12.5 per cent. This contains an available sulphur ingredient.

2,062,652 hand from compounds containing sulphur in ingredient consists of a rosin oil or rosin, saponifled with an aqueous solution of caustic potash to such an extent that the'final product comprises approximately 40 per cent of potash rosin soap, 9. maximum of 8 per cent of moisture, and a reaction approximately neutral. Other soaps may be used for this purpose, suchas the equivalent soda soaps, or certain sodium-sulphonated soaps, but we prefer to use the potash or soda rosin soaps indicated, .since. other soaps usually or diethylene glycol may be added in percentages ranging from 1.5 to 7.0 depending upon the hardness of the water and the acidity of the soluble oil.

These cutting oils are best evaluated by actual use, and comparative use of these novel products and the products heretofore available has indicated greatly enhanced properties in these novel cutting oils. For example, the oil set forth in Formula I when emulsified with Water in the proportions of one part of oil to ten parts of water, and subjected to comparative tests with a good non-sulphurized cutting oil available on the market enabled the user to obtain about double the tool life obtained with the competitive oil,

In a similar test, in which the oil of Formula II was emulsified one to four with water, it was found that tools lubricated with this emulsion yielded 900 pieces of work pertool grind while a good non-sulphurized competitive oil yielded only 150 pieces per grind.

Laboratory tests of such oils are of comparative value only as the best test is that of use. An indicative laboratory test does exist in the use of the Almenpin test machine, described by Mough'ey 81 Almen, (Proc. A. P. I. 1931 page -77), wherein a pin is rotated in bearings so designed that increasing pressures may be applied to the lubricated surface. This machine is widely used in such comparative evaluations. In the following tabulation, the results of test runs are given, wherein emulsions of the novel oils com-' Pounds per square Soluble oil i 1 4 before ure Formula T 4. Formula Tl +1500 Competitive o l A 2000 Competitive o l B 3000 Competitive oil 0... 1500 Competitive oil 1).- 5500 Competitive oil E..- 2500 Competitive 011 F 25m Competitive oils A to F inclusive are all compounds regularly supplied to the trade for the same purposes for which the novel oils of this invention are intended. No one of these oils All of these oils were tested as emulsions containing 'phur has been inga mixture 'of V Y amass:

one part of the soluble oil and ten parts of water.

The method of, compounding these oils is simply one of stirring in steam jacketed kettles fitted withpaddles at a temperature of 100? F. to

-. 150 F. until the product is uniform after which itis drawn ofl directly into containers for sale.

.Where used in the claims, the expression sulphurized base" .10

denotes a minera1 oil 'or'fatty oil, as described above, to which elementary sulcontained therein; either in solution or in loosely boundchemical combination, being available under conditions of cutting oil use to increase the load-bearing capacity of the lubricating compound; a r

We claim:

i. a lubricant of the class denoted asso1ub1'e cutting'oils", comprising a hydrocarbon oil, sufflcient emulsifying base to bring about substantially immediate. andpermanent emulsion in water of ordinary neutral quality, and a sul-' phurized-base'f, said last-named ingredient being present to an extent. suiiflcient to substantially increase the load-bearing. capacity of the compound. e g

2. A lubricant of the class denoted .as soluble cutting oils", comprising a hydrocarbon oil, sufcutting oils, adapted to readily form permastantially increase the flcient emulsifying base to bring about substantially immediate and permanent emulsion in water of ordinary neutral quality, and in the hydrocarbon oil, incorporated therein by heat treatment, suihcient sulphur to substantially increase the load-bearing capacity of the compound.=

3.A lubricant oi the class denoted as soluble cutting oils", adapted for use as a permanently stable emulsion in hard water, comprising a hydrocarbon oil, suflicient emulsifying base, to bring about substantially immediate and" permanent emulsion in water of ordinary neutral quality and softness, sumclent "sulphurized base" to sum load-bearing, capacity of the compound, and an additional amount of a water-hardness-correcting rosin soap of a strong 4. A lubricant oi the class denoted as .sbluble nently stable emulsions in water of ordinary neuadded by aprocess of heat treat-.

sulphur and oil, the sulphur m1 quality and containing meat sulphur to substantially increasethe performance of the lubricant, comprising from 10 to weight per centofanemulsifying agent, fromfi to25weight per cent of afs'ulphurized base", and from 85 to 25 weight per cent of alight hydrocarbon mineral oil.

5. A lubricant of the class denoted as soluble cutting oils",'adapted to readily form perma-' nently stable emulsionsin water of ordinary neu-' tral quality and containing suflicient sulphur to substantiallyincrease the performance of the lubricant, comprising from 10 to 50 weight per cent of an emulsifying base, and from 90 to 50 'weight per cent ofa light hydrocarbonlubricant oil in which there has been-incorporated, by heating with sulphur, from 0.5 to 4% of its weight of sulphur.

6. A lubricant of. the class denoted as "sohibie cutting oils", adapted for use as a permanently stable emulsion in hard water and containing.

sufllcient sulphur to substantially increase the.

performance of the lubricant, comprising the mixture set forth in claim 4 and in admixture therewith an additional amount of a rosinsoap of a strong alkali, in the amount of from 10 to- 30 weight per cent of the first mixture.

7. A soluble cutting oil lubricant having the following composition:

Emulsifying base .'.f 2 3 Sulphurized base" 10 Paraiilne oil 8. A soluble cutting -oil lubrlcanthaving the. following composition:

, l Per cent by weight I Emulsifying base 20 Mineral oil (containing 1.5% sulphur) all soluble cutting on lubricant having the following composition:

' Per cent by weigh t Emulsifying base 17.5 Sulphurized base"- 8.7. Parafline 62.3

Potash rosin soap 12.5

more a. mans. monoru: anonrmm. 

